Image Processing Device, Image Forming Apparatus, and Image Forming Method

Abstract

An image processing device includes: a first memory unit which receives screen data selected from a plurality of screen data stored in a second memory unit and transferred to the first memory unit, and stores the received screen data; and a third memory unit which has a first area for receiving first line data as line unit data of screen data stored in the first memory unit and transferred to the first area and for storing the first line data, and a second area for receiving second line data as line unit data of the screen data stored in the first memory unit and transferred to the second area and for storing the second line data.

1 . An image processing device comprising:
 a first memory unit that receives screen data selected from a plurality of screen data stored in a second memory unit and stores the received screen data; and   a third memory unit that has a first area for receiving first line data as line unit data of screen data stored in the first memory unit and for storing the first line data, and a second area for receiving second line data as line unit data of the screen data stored in the first memory unit and for storing the second line data.   
     
     
         2 . The image processing device according to  claim 1 , further comprising:
 a screen processing unit that reads the first line data or the second line data stored in the third memory unit and performs screen processing for print image data based on the line data thus read out; and   a reference signal producing unit that produces a reference signal based on which third line data as line unit of the screen data stored in the first memory unit is written to the third memory unit in synchronization with reading of the first line data or the second line data.   
     
     
         3 . An image forming method comprising:
 transferring first screen data selected according to types of transfer medium inputted by a transfer medium information input unit from a second memory unit that stores a plurality of screen data to a first memory unit, and storing the selected first screen data;   transferring first line data as line image unit of the first screen data stored in the first memory unit to a first area of a third memory unit and storing the transferred first line data in the first area, and transferring second line data as line image unit of the first screen data stored in the first memory unit to a second area of a third memory unit and storing the transferred second line data in the second area; and   reading the first line data to perform screen processing for print image data.   
     
     
         4 . The image forming method according to  claim 3 , further comprising:
 reading the first line data to perform screen processing for print image data, and then reading the second line data to perform screen processing; and   writing third line data as line image unit of the screen data stored in the first memory unit to the third memory unit based on a reference signal produced in synchronization with reading of the second line data.   
     
     
         5 . The image forming method according to  claim 3 , further comprising:
 a rotational image carrying body;   an exposure head that includes an image forming system Having negative optical power and light emission element forming an image by using the image forming system and disposed in the rotational axis direction and rotational direction of the image carrying body; and   switching arrangement of image data to which screen processing has been applied based on the screen data in the rotational axis direction and rotation direction of the image carrying body after reading the first line data and performing screen processing for print image data.   
     
     
         6 . An image forming apparatus comprising:
 a rotational image carrying body;   an exposure head which includes an image forming system having negative optical power and light emission element forming an image by using the image forming system and disposed in the rotational axis direction and rotational direction of the image carrying body;   a first memory unit that stores screen data;   a screen processing unit that performs screen processing based on the screen data stored in the first memory unit; and   a control unit that switches arrangement of image data to which screen processing has been applied based on the screen data stored in the first memory unit in the rotational axis direction and rotation direction of the image carrying body.   
     
     
         7 . The image forming apparatus according to  claim 6 , further comprising:
 a developing unit that develops a latent image formed on the image carrying body by using the exposure head;   a transfer material to which the image developed on the image carrying body by the developing unit is transferred;   a transfer unit that transfers the image transferred on the transfer material to a recording medium; and   a recording medium information input unit that inputs information on the recording medium transferred by the transfer unit.   
     
     
         8 . The image forming apparatus according to  claim 7 , Further comprising a second memory unit that stores first screen data associated with the type of the recording medium inputted to the recording medium information input unit, wherein:
 second screen data stored in the second memory unit is transferred to the first memory unit to be stored therein; and   the screen processing unit performs screen processing based on the first screen data stored in the first memory unit.   
     
     
         9 . The image forming apparatus according to  claim 6 , further comprising a third memory unit that writes line data as line image unit of the screen data stored in the first memory unit and reads the written line data. 
     
     
         10 . The image forming apparatus according to  claim 9 , wherein the third memory unit has:
 a first area to which first line data of the screen table is written; and   a second area to which second line data of the screen table is written,   and   the screen processing unit performs screen processing while reading the line data written to the first area, and   a reference signal producing unit produces a reference signal based on which third line data is written to the second area of the third memory unit in synchronization with the reading performed by the screen processing unit.   
     
     
         11 . The image forming apparatus according to  claim 8 , wherein the second memory unit has a plurality of screen data according to types of recording medium. 
     
     
         12 . The image forming apparatus according to  claim 8 , wherein the second memory unit has a plurality of screen data according to inputted attributes of print image data. 
     
     
         13 . The image forming apparatus according to  claim 8 , wherein the second memory unit has a plurality of screen data corresponding to gradation values of inputted print image data. 
     
     
         14 . The image forming apparatus according to  claim 8 , wherein:
 the screen data stored in the second memory unit is selected according to information about recording medium inputted to the recording medium information input unit, attributes of the inputted print image data, and gradation values of the inputted print image data; and   the selected screen data is transferred to the first memory unit.